35v 50w LED Cob driver from 50v PSU

Discussion in 'Power Electronics' started by elephunk, Jan 14, 2018 at 6:59 AM.

  1. elephunk

    Thread Starter New Member

    Nov 21, 2016
    26
    0
    Hey everyone, I'm still learning and have a project that I could do with some help if someone doesn't mind.
    So I would like to build some lights into my shed and control them with ESP8266, 5x 50w 32-35v COBs rated for 2800mA. I have a 20A 50v power supply already fromqq a Network Switch which was a bargain, works wonders and is just begging to be used, so I would prefer not to buy a driver for the LED's. I am looking at building a driver myself and was initially thinking of using some LM2596HV buck converter circuits (One for each COB) to get me down to 32-35v and then use separate PWM circuits to control the brightness of each COB.

    Since researching the situation I have discovered the LT3763 LED Driver Buck IC, 60v Input, up to 25A output, current limiting, PWM and everything. Looks perfect to me for my project as I can merge 5 channels into 1 and cut down my circuit drastically.
    This is the circuit I am looking at basing my design on.
    dn508f1a.png

    The current is limited by the 5mOhm resistor between Sense+ and Sense- then trimmed down by the 50k pot on Ctrl1.

    So my questions, can I
    1) Connect this chip up via its PWM pin to an ESP8266 and control it??
    2) Can I replace the 50k Pot with a Ddigital Pot connected to an ESP8266 and control it??
    3) If yes to both, what is everyone's preference on how to control high power LED's, current limiting or PWM??

    Thanks in advance
    Iain
     
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